This invention relates generally to projection display systems using microdisplay imagers.
Projection display systems may be used to project a high resolution display onto a larger area. A microdisplay may create an image which is projected onto a projection screen. With the advent of high definition television systems, digital cinema projectors, and high density graphic display monitors, the need for higher resolution is increasing.
Projection display systems based on various microdisplay technologies such as liquid crystal-on-silicon (LCOS), digital light processor (DLP) using digital micromirror devices (DMD), and high temperature polysilicon (HTPS) based transmissive liquid crystal display panels are available on the market with about one megapixel resolution. However, there is a need for displays with spatial resolutions on the order of 2 megapixels and higher and it would be highly desirable to reduce the cost of these systems.
Each of those imager panels modulates light that originates from a lamp of a projection display system. In typical projection display systems, the light output is formatted with optics to deliver a uniform illumination level onto the surface of the imager. The imager forms a pictorial image by modulating the illumination into spatially distinct tones, ranging from dark to light, based on supplied video data. Additional optics then relay and magnify the modulated illumination pattern onto a screen for viewing.
The imager typically includes an array of pixel cells, each of which is electrically controllable to establish the intensity of a pixel of the projected image. In some projection display systems, images are transmissive and in other they are reflective. For present purposes, both transmissive and reflected images are contemplated.
Thus, there is a need for system-level enhancement of the image resolution that provides ways to achieve higher resolution on the screen of the projection display systems than that directly provided by the imagers employed in the systems.